Early events in the mechanism of single-source chemical vapor deposition of zirconium and hafnium diboride: a computational investigation

Prokvolit, Sergei; Mao, Erqian; Gray, Thomas G.

doi:10.1039/d3cp05385g

Cited by 1 publication

(2 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A recent related computational study considered the decomposition pathways of Hf(BH 4 ) 4 and Zr(BH 4 ) 4 to understand the early events in the CVD growth of MB 2 thin films. 35 However, that study did not consider surface reactions. In the case of ZrB 2 film growth, after the initial decomposition takes place, subsequent growth necessarily occurs on a ZrB 2 surface.…”

Section: Introductionmentioning

confidence: 99%

“…The calculated frequencies and intensities for BH, HBBH, and Zr–HBBH–Zr together provide good agreement with the experimental RAIR spectra. A recent related computational study considered the decomposition pathways of Hf(BH 4 ) 4 and Zr(BH 4 ) 4 to understand the early events in the CVD growth of MB 2 thin films . However, that study did not consider surface reactions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Identification of a Stable B₂H₂ Intermediate in the Decomposition of Zr(BH₄)₄ on the Pd(111) Surface

Ranjan,

Redington,

Ologun

et al. 2024

J. Phys. Chem. C

View full text Add to dashboard Cite

Tetrakis(tetrahydroborato)zirconium(IV), Zr(BH 4 ) 4 , is a volatile compound that has been widely used as a singlesource precursor to grow carbon-free thin films of zirconium diboride by chemical vapor deposition (CVD) on a wide range of substrates that include oxides, semiconductors, and metals. However, the basic surface chemistry of the compound that underlies the initial stages of the CVD process is largely unknown for any substrate. We studied the adsorption and decomposition of Zr(BH 4 ) 4 on a Pd(111) surface with the experimental techniques of reflection absorption infrared spectroscopy (RAIRS), temperatureprogrammed reaction spectroscopy (TPRS), and X-ray photoelectron spectroscopy (XPS) and with density functional theory and first-principles molecular dynamics simulations. After exposing Pd(111) at 90 K to Zr(BH 4 ) 4 (g), a RAIR spectrum was obtained that closely matched that of the pure compound, indicating that it adsorbs without dissociation at 90 K. However, upon heating to 200 K the RAIR spectrum undergoes dramatic changes indicating that a new surface species is formed that retains both terminal B− H bonds and bridging metal−H−B bonds, as indicated by B−H stretches in the ranges of 2563−2540 and 2143−2135 cm −1 , respectively. Hydrogen desorption is first observed at around 178 K and the presence of a stable hydrogen-containing surface intermediate is revealed by additional H 2 desorption peaks at 330 and 426 K. A combination of theoretical methods reveals that BH adsorbed at a 3-fold hollow site on the Pd(111) surface is the most stable species, but once formed two BH molecules can dimerize to form HBBH. A stable configuration for B 2 H 2 is achieved through formation of B−H---Zr bridge bonds with a Zr atom located at one or both ends of a B 2 H 2 molecule. Calculated vibrational frequencies and intensities provide an excellent match with the experimental RAIR spectra.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Identification of a Stable B₂H₂ Intermediate in the Decomposition of Zr(BH₄)₄ on the Pd(111) Surface

Ranjan,

Redington,

Ologun

et al. 2024

J. Phys. Chem. C

View full text Add to dashboard Cite

show abstract

Early events in the mechanism of single-source chemical vapor deposition of zirconium and hafnium diboride: a computational investigation

Abstract: Chemical vapor deposition (CVD) of group 4 metal-diboride ceramics from a single source is a versatile technique that finds many applications from hypersonic flight to microelectronics.

Cited by 1 publication

References 65 publications

Identification of a Stable B₂H₂ Intermediate in the Decomposition of Zr(BH₄)₄ on the Pd(111) Surface

Identification of a Stable B₂H₂ Intermediate in the Decomposition of Zr(BH₄)₄ on the Pd(111) Surface

Contact Info

Product

Resources

About

Early events in the mechanism of single-source chemical vapor deposition of zirconium and hafnium diboride: a computational investigation

Abstract: Chemical vapor deposition (CVD) of group 4 metal-diboride ceramics from a single source is a versatile technique that finds many applications from hypersonic flight to microelectronics.

Cited by 1 publication

References 65 publications

Identification of a Stable B2H2 Intermediate in the Decomposition of Zr(BH4)4 on the Pd(111) Surface

Identification of a Stable B2H2 Intermediate in the Decomposition of Zr(BH4)4 on the Pd(111) Surface

Contact Info

Product

Resources

About

Identification of a Stable B₂H₂ Intermediate in the Decomposition of Zr(BH₄)₄ on the Pd(111) Surface

Identification of a Stable B₂H₂ Intermediate in the Decomposition of Zr(BH₄)₄ on the Pd(111) Surface